1. Field of the Invention
This invention relates to vehicular instruments, and more particularly to an illuminant pointer needle for vehicular instruments.
2. Description of the Prior Art
Heretofore, there have been known various vehicular instruments employing an illuminant pointer needle for the purpose of enhancing the visibility of the pointer needle, especially for enhancing its nighttime visibility.
In such instruments, it has been the usual practice to locate a light source such as an incandescent lamp or the like in the vicinity of a pointer needle and to guide light to the pointer needle through a light guide member of transparent acrylic resin material, or to mount a light-emitting element like an incandescent lamp or a light-emitting diode on the pointer needle itself for direct illumination thereof. In these cases, the pointer needle has a colored layer applied to the lower side of an index portion by hot stamping or other suitable means, so that one can recognize the needle by way of the color of the applied coloring layer which reflects external light during the daytime and by the light of illumination from the light source during the nighttime.
Namely, in any case the needle has the same color which is determined by the color of the layer applied to the index portion of the pointer needle both in the daytime when the needle is not illuminated and in the nighttime when the needle is illuminated. Therefore, depending upon the color of the applied layer, the visibility of the needle varies from daytime to nighttime, giving rise to a problem that the visibility of the pointer needle drops to an objectionable degree in terms of safety.